Tool for unwrapping wrapped wire connections



Sept. 3, 1957 Filed Oct. 22, 1954 lNVE/VTOR By FRECK Mam ATTORNEY UnitedStates Patent.@

Too Fon UNWRAPPING wRmzrimwmE coNNneno s.

FrankReck, Flushing, N. assignor t'o Bell Telephone Laboratories;Incorporated; New York 'Nt Ya, a corporation of New York This inventionrelates towi-re handling tools and more particularly to a tool forremoving. a wrapped; wire connection' from a terminal.

As set forth in Patent 2,585,010. tol-Iickman, Mallina andwReck, anelectrical connection. canbe: made to a; suitable terminal with propertools by wrapping a wire around the terminal. Tools such as the onedisclosed in the noted patent or in applicants Patent 2,649,121, issuedAugust 18, 1953, will wind or wrap a connection of this type.

In connection with making repairs, alterations, etc., it often becomesnecessary to remove wrapped wire con nections. This may be done bybodily pulling the coil or Wrapping of wire from the terminal by meansof a tool having a hook or lug to go behind the coil. The operation isin the nature of wheel or gear pulling. However, since the adherence ofthe coiled wire to the terminal is rather tenacious in a properlyWrapped connection, terminals, particularly those of small section, maybe broken by such an operation.

A wrapped connection may be unwrapped by unwinding the connection wirefrom the terminal. For example, the end of the wire may be grasped by asuitable tool, such as a pair of pliers, and unwound. Such an operationis time-consuming and also rather diflicult to perform where theterminal spacing is slight.

An object of this invention is to expedite the removal of wrapped wireconnections from terminals without damaging the terminals.

A feature of this invention resides in a tool having a helically formedend for picking up and loosening successive turns of the wrapped wire sothat it may be easily withdrawn from the terminal.

A more specific feature of the invention is an unwrapping toolcomprising a substantially cylindrical bar or rod having an axial,terminal-receiving bore or opening in one end and a spiral or helicalland defining a groove around said end.

A feature of the tool of this invention lies in the knife edge or wedgeformation of the outer end of the helical land or ridge that bounds thegroove, whereby said outer end may be easily inserted between the end ofthe wire wrapping and the adjacent turn.

A further feature of the tool of this invention resides in a smallflattened area or relieved portion immediately back of the tip on theouter surface of the wedge-shaped end to avoid gouging of the Wire andconsequent interference with the loosening of the turns.

Other and further objects and features of this invention will appearmore fully and clearly from the following description of exemplaryembodiments thereof taken with the appended drawing in which:

Fig. l is a perspective view of an embodiment of the invention;

Fig. 2 is a view in elevation of the grooved end of the tool of Fig. 1;

Fig. 3 is a further enlarged view somewhat exaggerated to show the flaton the outside of the wedge-shaped tip;

F-ig. 41isa View in elevation showing the tool, of Fig. 2' applied to;aterminal with the wedge-shaped tip inserted between theend of the coilportion of the wrapped con nection and an adjacent turn thereof; and

Fig. 5 is a view similar to that of Fig. 2 of the outer end. of amodified unwrappingltool.

The unwrapping tool shown in Fig, l is; a hand tool. having a reduced.end portion. 10 withthe spiral groov'e'll} therein. The'h'andl'efportion 12] has. a knurled or otherwiseroughened' grip poftion I31;Theend portion. 1'0 is. of a diameter 'suchjtliattlie spiral 1 1 iscomparable in size to the coil. or wrappedj'po'rfion oftl'ie connectionto be unwrapped.v The liandlegportion may be, of some what greaterdiameter than the, end portion. 10 in. the interest of. ease ofhandling. f

As maybe seen inthe-enlarged view of Fig- 2f,,the tool. is provided withan axialopeuing or; bore 14.1fm rgeceiv= i'ngja. terminal 'sucli astli'e terminal 20 of" Fig. 3.

The spiral of helical groove 11, should?v have a pitch: greater thanthat of the connection't'o" be 'iinwrapped. Advantageously, the groovepitch is 2 to 4 times that of the wire coil or wrapping of theconnection.

The ridge or land 15 between the convolutions of the groove 11 tapers towedge form at the tip 16. The extreme end of the tip has on the outersurface a small flat area, as shown at 17 in Fig. 3. This is somewhatexaggerated in the drawing in the interest of clarity of illustration.This slight relieving of the wedge surface avoids gouging of the wire bythe Wedge tip and consequent jamming of the tool in some instances. Forexample, with very fine terminals and wire, the additional friction dueto gouging may be enough to cause the tool to push the wire rather thansliding over it and to twist off the terminal. It may be noted here thatthe wrapped connection is ordinarily not a true helix, the turns on theflat side of a terminal being somewhat S shaped, as shown in Fig. 4.Thus the outer edge of the wedge encounters a slight depression followedby a rise in travelling over the bottom part of the S, which wouldincrease the gouging tendency if it were not for the flat 17. 7,

As shown in Fig. 4, the tool is applied to a wrapped connection so thatthe terminal 20 enters the opening 14. The tool is then rotated in thedirection of the arrow 24 so that the wedge-shaped tip 16 enters thewrapping between its end 21 and the adjacent turn 22. The end 21 of thewire is directed into the groove 11 of the tool, and continued rotationof the tool loosens the whole wrapping which may then be removed.

As shown in Fig. 5, the outer end of portion 30 of the tool may betapered, and the groove 31 may be of decreasing depth as it recedes fromthe tip. This construction opens up the turns of the wrappingsufficiently so that when the opening 34 is removed from the terminalafter unwrapping, the wire tends to drop free from the tool. Thislatter-described construction may be varied by having only the taperwith a groove of constant depth with reference to the taper, or only theshallowing groove with no taper. In either case the root radius of thegroove will increase as the groove recedes from the tip, thus enlargingthe diameter of the wrapping as it is loosened.

It is noted that the tool illustrated is used by rotation in acounterclockwise direction, as indicated by the arrow 24 in Fig. 4. Ifit is necessary to unwrap connections of the other hand than that shownin Fig. 4, a tool adapted for operation in a clockwise direction may beused. Such a tool could be on the other end of the handle 12, forexample.

Where it is desirable to use a power drive with a tool of this type, thetool may be formed on the end of a bit adapted to be held in the chuckof a hand drill, used in place of the screwdriver bit in a powerscrewdriver or in other suitable drive means. also be combined with apower or hand driven wrapping tool.

Various modifications may be made in this tool without departing fromthe spirit and scopeof theinvention,

For example, the number of convolutionsfofthe groove 11 or the groove31' may be varied within reasonable,

limits.

What is claimed is:

1. A tool for unwrapping a wrapped wire connection from a terminal, saidtool comprising an elongated bar having in one end thereof asubstantially axial terminal receiving opening, and on the surfacethereof and spaced from said opening a helical ridge, adjacentconvolutions of which define a wirereceiving groove extending to saidend, the groove bounding faces of said ridge tapering to define awedge-shaped tip at the outer end thereof, and means for rotating saidbar.

2. A tool as in claim 1 in which the outer surface of the wedge-shapedtip is flattened for a short distance.

3. A tool as in claim 1 in which the outer surfaceof the wedge-shapedtip immediately adjacent the end thereof has a relieved portion.

This unwrapping tool may 4. A tool for unwrapipng a wrapped wireconnection from a terminal, said tool comprising a cylindrical bar, asubstantially axial terminal receiving opening in one end of said bar,and on the surface of said bar a helical ridge defining between itsconvolutions a helical wire receiving groove extending to said end andcommunicating with said opening only at said end, the groove boundingfaces of saidridge tapering to define a knife edge at the outer endthereof, and means for rotating said bar.

5. A tool as in claim 4 in which the surface of the knife edge thatfaces said end is flattened for a short dis tance back from the edge.

6. A tool as in claim 4 in which the surface of the knife edge thatfaces said end has a relieved portion immediately adjacent the edge.

References Cited in the file of this patent UNITED STATES PATENTSAbramson et a1 Jan. 7, 1936

